Polymers of an unsaturated alkyd resin and an unsaturated halogenated compound and method of producing same



Patented Oct. 5, 1948 POLYMERS OF AN UNSA'I'URATED ALKYD RESIN AND ANUNSA'ITURATED HALOGEN- ATED COMPOUND AND METHOD OF PRO- DUCING SAMEBlrgel' W. Nordlander, Schenectady, N. Y., as-

signor to General Electric ration of New York Company, a corpo- NoDrawing. A plication April 39, 1946, Serial No. 666,203

Claims. 1

This application is a continuation-in-part of my copending a plicationSerial No. 302,165, filed October 31, 1939, now abandoned and assignedto the same assignee as the present invention. This invention relates tothe production of new materials having valuable and characteristicproperties that make them especially suitable for use in industry, forexample inmolding, laminating, casting, coating and adhesiveapplications, and for other purposes. The invention is concerned moreparticularly with compositions of matter comprising an interpolymer(copclymer) -or interpolymers of copolymerizable ingredients includingat least one polymerizable polyhydric alcohol ester of an alphaunsaturated alpha beta polycarboxylic acid (hereafter for brevitydesignated generally as an "unsaturated alkyd resin and is not intendedto include the conventional drying oil-modified alkyd resins) with atleast one polymerlzable polyester compatible with the unsaturated alkydresin and obtained by esterifying a nuclearly halogenated aromaticpolycarboxylic acid or anhydride, e. g., monobromophthalic,monochlorophthalic, dichlorophthalie,

dibromophthalic, trichlorophthalic, tetrachlorophthalic acids oranhydrides, etc., with an unsaturated monohydric alcohol, e. g., allylalcohol.

The polyesters of unsaturated monohydric alcohols used in carrying thepresent invention into efiect may be considered as being members of theclass of esters which may be represented by the formula where R is amember of the class consisting of Thus, R may be, for example, an alkylradical such a methyl, ethyl, propyl, isopropyl, butyl, secondary-butyl,isobutyl, amyl, isoamyl, hexyl, octyl, etc.; and aralkyl radical, e. g.,benzyl, phen ylethyl, phenylpropyl, etc.; a carbocyclic radical such,for example, as phenyl, cresyl, halo-phenyl, xylyl, tolyl, naphthyl,cyclohexyl, methylcyclohexyl, etc.; and Y is a radical-of a nuclearly 2halogenated aromatic polycarbox ylic acid, e. g., halogenaphthalic, e.g.. tetrachlorophthalic acid or anhydride,halogenoterephthalic,halogenoisophthalic, halogenobenzophen one 2,4 dicarboxylic,halogenodiphenic, halogenonaphthalic, etc. Any of the halogenderivatives of aromatic polycarboxylic acids may be employed but Iprefer to use the chloro derivatives. For purposes of brevity the termsnuclearly halogenated polycarboxylic acid and "nuclearly halogenatedaromatic dicarboxylic acid, as used generally herein and in the appendedclaims, are intended to include within their meaning the halogenatedaromatic polycarboxylic acids, that is. aromatic polycarboxylic acidscontaining halogen in the aro matic nucleus.

From the above formula, it will be seen that polyesters, the alcoholradicals of which contain the grouping are embraced by this invention.The term polyallyl ester of a nuclearly halogenated aromaticpolycarboxylic acid as used generally herein and in the appended claimsis intended to include within its meaning polymerizable esterificationproducts of unsaturated monohydric alcohols, such as above indicated byway of example, with a nuclearly halogenated aromatic polycarboxylicacid having at least two esterifiable carboxy groups and at least oneand not more than four halogens attached to the aromatic nucleus, thenumber of halogens present depending in some measure on the number ofcarboxy groups. In the preferred embodiments of the invention, I preferto use a compound wherein the aromatic nucleus contains four halogens inthe ring and two carboxy groups, e. g,, diallyl tetrachlorophthalate.

Compositions produced in accordance with my invention are especiallyadapted for use as -solventless varnishes, for instance as coatingcompositions and binders in theproduction of laminatedsheets and tapesfor use in insulating electrical devices, as well as for otherapplications.

It has long been recognized that the varnishes heretofore commonly usedin such applications as above mentioned possess certain inherentdisadvantages which it has not been possible to overcome or eliminate inspite of many efforts. These varnishes have one common characteristic,that is, they contain an inert, volatile, solvent which must be expelledduring the curing process. In addition, many of the resin bases used insuch varnishes require the absorption of oxygen from the atmosphere fortheir conversion into an insoluble and infusible condition. when suchvarnishes are used as binders in the production of electrical insulationof substantial thickness. as for instance in the case of laminated micaflake insulation of coils and bars for high voltage equipment, it is avery difllcuit task completely to remove all the solvent from theinterior of the insulation layer. Usually the coil or bar has to begiven a long heat treatment under reduced pressure. However, during thistreatment the outer part of the insulation layer commences to cure,which action tends to seal the coil. This hinders both the escape of thesolvent from the interior of the insulation and a thorough cure of thewhole mass. The pressure or entrapped solvent in the insulation may leadto very serious difliculties. When a coil is subjected to an increase intemperature, such as takes place in the operation of the equipment ofwhich it is a part, an internal pressure will be exerted on theinsulation where the solvent is entrapped. This entrapped solvent alsohas a softening action upon the varnish base with obvious disadvantages.This combination of effects may result in voids forming in the interiorwith a resulting pulling of the mass. Due to the corona formed in thesevoids under the high voltage stress, the dielectric strength of theinsulating material is impaired. In addition, the presence of uncuredlow molecular weight material in the binder may cause the dielectriclosses to increase.

Due to the above-described difllculties there has long been a need inthe electrical industry for a type of non-volatile, fluid varnishsuitable for insulation applications, which varnish would eliminate thenecessity of removing solvents and the need of absorbing oxygen from theatmosphere.

during curing and which, furthermore, would cure through completely evenin large thicknesses.

I have discovered that all these requirements can be attained verysatisfactorily by forming a mixture comprising an unsaturated alkydresin or resins and a polymerizable polyallyl ester or esters of anuclearly halogenated aromatic polycarboxylic acid (as above defined),which ester is compatible with the alkyd resin component and whichmixture also preferably contains a polymerization catalyst; applying themixture to the materials to be coated or bonded together or otherwisetreated; and treating the mixed components as hereafter more fullydescribed to form an inter-polymer of the same.

A very practical advantage accruing from my invention is that itprovides new compositions adapted for the production of cast or moldedmassive bodies. The unsaturated alkyd resins alone are unsuited, even inthe presence of polymerization catalysts such as peroxides, for thepreparation of practically useful cast or molded articles of substantialsize. If effort be made to prepare commercially useful massive bodiesfrom the unsaturated alkyds alone, even prolonged heat treatment in thepresence of a polymerization catalyst usually gives unsuitablematerials. The cast or molded articles generally are filled with bubblesor show cracks, or both, when cured.

In carrying the present invention into effect an unsaturated alkyd resinis first prepared in accordance with technique now well known to thoseskilled in the alkyd resin art. Any polyhydric alcohol containing atleast two esteriflable aliphatic hydroxyl groups, or mixtures of suchalcohols, may be used in producing the unsaturated alkyd resin. Examplesof such polyhydric (dihydric. trihydric, etc.) alcohols are ethyleneglycol, diand tri-ethylene glycols, propylene glycol. trimethyleneglycol. glycerine, pentaerythrltoi, etc. It is understood, of course,that modifications with monohydric alcohols may also be made byincorporating a monohydric alcohol at the time the unsaturated alkydresin is prepared. Examples of such monohydric alcohols arecyclohexanol, 2-ethylhexanol, undec-anol, phenyl cellosolve (ethyleneglycol monophenyl ether), butyl cellosolve (ethylene glycol monobutylether), methyl carbitol (diethylene glycol monoethyl ether) carbitol(diethylene glycol monoethyl ether), etc. Examples of alpha unsaturatedalpha beta polycarboxylic acids, or mixtures or such acids, which may bereacted with the polyhydric alcohol or alcohols to form the unsaturatedalkyd resin are maleic, iumaric, itaconic, messaconic, etc. Ifavailable, anhydrides of these polycarboxylic acids maybe employed. Theterms polycarboxylic acid and dicarboxylic acid as used generally hereintherefore are intended to include within their meanings the anhydridesof such acids.

' The polyesters of unsaturated monohydric alcohols used in carrying thepresent invention into effect may be symmetrical or unsymmetricalpolyesters such as the diallyl, dialkallyl (e. g., dimethallyl,diethallyl, dipropallyl. etc.), allyl methallyl, ally] ethallyl, etc.,esters or nuclearly halogenated aromatic polycarboxylic acid such, forinstance, as nuclearly halogenated phthalic, isophthalic, terephthalic,benzophenone-2,4' dicarboxylic acids, etc., or the anhydrides of suchacids if available. I prefer to use the simple instead of mixedpolyesters, more specifically diallyl and the dimethallyl and otherdialkallyl esters of nucleariy halogenated phthalic acid or anhydride.The only requirement of the polyallyl ester is that it be polymerizableand that it be compatible with the particular unsaturated alkyd resinemployed. The solubility or compatibility of the components with respectto each other depends, for example,

upon the particular polyhydric alcohol used in making the resin and thelength of the chain in the allyl ester radical. In general, the longerthe chain in the allyl radical, the less compatible is the polyallylester with the unsaturated alkyd resin.

In effecting interpolymerization between the polymerlzable estersemployed in practicing my invention I prefer to use a small amount of apolymerization catalyst accompanied by heat, light, or heat and light.Examples of catalysts which may be used are ozone and ozonides;inorganic super-oxides such as barium peroxide, sodiumperoxide, etc.;dialkyl peroxides such as lauryl peroxide, stearyl peroxide, etc.;symmetrical diacyl peroxides, e. g., acetyl peroxide, lauroyl peroxide,stearoyl peroxide, benzoyl peroxide, etc.; unsymmetrical or mixed diacylperoxides, e. g., acetyl benzoyl peroxide, etc.; peraclds, e.'g.,peracetic acid, etc.; terpene peroxides such as ascaridole, etc.;peroxides of the drying I oils such as those formed upon oxidation oflinseed oils, etc.; and various other percompounds such, for instance,as perborates, e. g., sodium and potassium perborates, etc. persulfates,e. g., sodium and potassium persulfateaetc; perchlorates, e. g., sodiumand potassium perchlorates,

etc. Chlorates such, for instance, as sodium and potassium chloratesalso may be used as polymerization catalysts. Benzoyi peroxide is thepreferred catalyst. Any suitable catalyst concentration may be used but,in general, the catalyst concentration will be within the range of 0.1to 2.0 per cent by weight of the whole.

When rapidity of copolymerization is of secondary importance,copolymerization between the components may be eflected merely underthe-influence of heat, light, or heat and light and in the ,absence ofan accelerator of polymerization. The rate of copolymerization and theproperties of the final product vary with the time, temperature and, ifa catalyst is used, also with the catalyst concentration.Copolymerization; may be efiected at from room temperature (20-30- C.)to temperatures above 100 0., for example about 130 (2., but ordinarilyI use temperatures within the range of about 80 to 130 C. in causing themixed or dissolved components to interpolymerlze.

In order that those skilled in the art better may understand how thepresent invention may be practiced, the following illustrative examplesthereof are given. All parts are by weight:

The compound, diallyl tetrachlorophthalate, was prepared in thefollowing manner:

A prox. Parts 01 Ratio Ally alcohol 232-0 4 Tetrachlorophthalicanhydride 288. 0 1 d-Camphor sulionlc acid 27. 6

The above ingredients were mixed together in' a S-necked, glass,round-bottom flask. equipped with a thermometer, a sealed stirrer, and ashort take-off column attached .to a water condenser. The mass washeated at its reflux temperature (about 85-90 C.) for about 13 v hourswhile the distillate was collectedin a separate vessel. After this time,about 116 parts allyl alcohol were added to the reaction mixture, andthereflux continued for an additional3 hours. The residue in the flaskwas washed with water and sodium carbonate until it was. neutral tolitmuspaper. The viscous oily layer was extracted with other by repeatedwashings and dried over anhydrous CaClz. The ether solution wasdistilled to remove the ether and the resulting liquid was fractionallydistilled to obtain a fraction boiling between 189-191 C. at about 1.6min, This fraction, which was solid at room temperature, was furtherpurified by recrystallization from petroleum ether to yield about 77parts (approximately 20% of the theoretical) of substantially purediallyl tetrachlorophthalate melting at about 73- 74 C.

, Example 1 Parts Diethylene glycol maleate 25 Diallyltetrachlorophthalate 25 containing 0.25 part benzoyl peroxide yielded avery tough, hard, slightly cloudy, insoluble and infusible copolymerwhen heated for 24 hours at 80 and 24 hours at 100 C.

Example 2 Parts Diethylene glycol maleate 20 Diallyltetrachlorophthalate 40 Iii Example I Parts Dipropylene glycol maleate25 Diallyl tetrachlorophthalate 25 having incorporated therein 0.25 partbenzoyl peroxide gave an insoluble, infusible, clear, hard but somewhatbrittle copolymer when heated for 6.5 hours at 80 and 25 hours at 100C,

Example 4 s Parts Glyceryl cyclohexyl maleate 25 Di-allyltetrachlorophthalate 25 individual components until, say, an acid valueof the order of 20 to 50 had been obtained. A slight molecular excess ofthe glycol was used in each case better to cause the reaction to go tocompletion. It will be understood, of course, by those skilled in theart that proportions other than approximately equimolecular quantitiesmay beemployed. For instance, in Example 4, 1 mol glycerine, 3 molscyclohexyl alcohol and 3 mols maleic anhydride were caused to react witheach other in order to obtain an alkyd resin having an acid value of25-30. The ratio of the polyhydric alcohol to the polycarboxylic acidwill vary depending on the particular service application.

' In certain cases, instead of copolymerizing a single polymerizablepolyallyl ester of a nuclearly halogenated aromatic polycarboxylic acidwith a single polymerizable unsaturated alkyd resin, I may copolymerizea plurality of such esters either with a single unsaturated alkyd resinor with a plurality of such resins. In this way it is possible to obtaina composition comprising a. mixture of interpolymers best adapted tomeet a particular service application.

It will lie-understood, of course, that myinvention is not limited tothe particular proportions of the individual components given in theabove illustrative examples, and that the proportions may be varieddepending upon the particular properties desired in the interpolymer.Thus, the incorporation into an unsaturated alkyd resin of as little as5 per cent of certain polymerizable polyallyl esters of a nuclearlyhalogenated aromatic polycarboxylic acid, for example, diallyltetrachlorophthalate and dimethallyl tetrachlorophthalate, yieldscopolymers of improved properties as compared with unsaturated alkydresins which have been polymerized in the absence of such esters.Depending upon the particular purpose for which the material is to beused, the percentage proportions of the initial components generally arewithin the range of 10 to 90 per cent of the polyallyl ester to 90 to 10per cent of the unsaturatedalkyd resin, the referable range being from15 to 75 per cent of the former to to 25 per cent of the latter.

The in'terpolymerization products of this invention have awide range ofproperties. Depending upon the particular starting components, theparticular proportions thereof, the conditions of polymerization and theextent of the interpolymerization, they vary from soft, flexible,soluble bodies to rubbery and hard, rigid masses of varying resistancesto solvents. In intermediate stages assumes of copoiymerizatlon someform fluid compositions of varying intrinsic viscosities andmay be soused. For coating and impregnating applications where the presence of asmall amount of solvent in the cured composition is not objectionable,the mixed polymerizable materials may be .diiuted with volatile ornonvolatile solvents to viscosities best adapted to meet the particularservice application, and then may be copolymerlzed after application ofthe solution to the particular article to be coated or impregnated. Bysuitable selection of the starting materials and the conditions ofinterpolymerization, interpolymers can be obtained in an insoluble,infusible state practically resistant to the destructive effect of otherchemical bodies such as acids, bases, solvents and the like.

These new inter-polymers or a mixture of the copolymerizable materialsmay be used alone or with fillers or other modifying agents, forexample, in casting and molding applications, as adhesives, impregnantsand surface-coating materials. They may be used as impregnants for manyporous bodies, such as cork, pottery, felts, or fabricated bodies withinterstices, e. g., the windings of electrical. coils, netted fiber,interwoven fibrous materials, etc. They also may be used forprotectively coating impervious articles such as metals, or for coatingor coating and impregnating articles such as paper, wood, cloth, glassfibers in felted, woven or other form, concrete, synthetic boards, etc.

mixed components or partial interpoiymers there of, with or withoutmodifying agents, may be cast and molded under heat or under heat andpressure. They also may be molded by injection, extrusion or compressionmoi technique whereby they are heatand pressure-hardened to yield moldedarticles of manufacture for various industrial, household and noveltyuses.

The poiymerizable compositions of this invention are especially adaptedfor use as "solventless varnishes, for example, in electricallyinsulating applications such as in the production of winding tapes.Thus, they may be used as a binding agent for mica in making a micatape. In producing mica tapes 9. suitable flexible, sheet insulatingmaterial such as cellulose itself and cellulose derivatives, forexample, Japanese tissue paper, cellulose esters and ethers such a.cellulose acetate, ethyl cellulose, etc., is coated with the vamish andupon this is placed flake mica also wetted with the varnish, followedusually by. another layer of flexible sheet material, which also iscompletely wetted with the varnish. Upon curing the resin bond in situat temperatures of the order of 80 to 100 C., a unitary laminated micaproduct is obtained.

By copolymerizing unsaturated alkyd resins with these unsaturatedmonohydric alcohol esters of nuclearly halogenated aromaticpolycarboxylic acids, interpoiymers of high resistance to flame can beproduced. Such flame-resisting compositions are especially suitable foruse in electrically insulating applications.

It will, of course, be understood that other nuclearly halogenatedaromatic polycarboxyllo acids or anhydrides may be employed in preparingpolyaliyl esters of the nuclearly halogenated aromatic polycarboxyllcacids or anhydrides. Among these may be mentioned 4-chlorophthalic acid,4-bromophthalic anhydride, 3,6-dichlorophthalic acid or anhydride,3,6-diiiuorophthalic acid, 3,4,6- trichlorophthalic acid or anhydride,3,4,6-triiodo- They also may be' employed in the production of wireenamels. The

8 phthalic acid v or anhydride, tetrabromophthalic, tetrafluorophthalicacids or anhydrides, etc. Nuclearly halogenated aromatic polycarboxylicacids or anhydrides other than the nuclearly halogenated phthalic acidsor anhydrides may also be used, e. g., the nuclearly halogenatedterephthaiic, lsophthalic, naphthalic, etc, acids or anhydrides. What Iclaim as new and desire to secure by Letters Patent of the United Statesis:

1. A product comprising an interpolymer of a dialiyl ester of anuclearly chlorinated phthalic acid and an unsaturated alkyd resin, theallyl residues of the diallyl ester being unsubstituted, and the twoingredients comprising the inter- .polymer being compatible andcopolymerlzable.

2."A product comprising an interpolymer of a.dially1 chlorophthalate andan unsaturated alkyd resin, the aliyl residues of the diallyl esterbeing unsubstituted, and the two components comprising the interpolymerbeing compatible and copolymerizable with each other.

3. A composition comprising an interpolymer of diethylene glycol maleateand a diallyl ester of a nuclearly chlorinated phthalic acid, the allylresidues of the diallyl ester being unsubstituted and the two componentsof the interpolymer being compatible and copolymerizable with eachother.

4. As a new product an interpolymer of diallyl tetrachlorophthalate andan unsaturated alkyd resin, the two components of the interpolymer beingcompatible and copolymerizable jwitheach other.

5. A polymerizable composition comprising (1) an unsaturated alkyd resinand (2) a diallyl ester of a nuclearly chlorinated phthalic acid, theallyl' residues of the dlailyl ester being unsubstituted, and theingredients (1) and (2) being copolymerizable and compatible with eachother.

6. A polymerlzable composition comprising (1) an unsaturated alkydresin, (2) diallyl tetrachlorophthalate, and (3) a polymerizationcatalyst for accelerating the oopolymerization of the materials of (1)and (2).

7. The method of producing an insoluble and infusible resinouscomposition which comprises (a) forming a mixture of (1) an unsaturatedalkyd resin, (2) a diallyl ester of a nuclearly chlorinated phthaiicacid, the allyl residues being free of substitution, and (3) a catalystfor accelerating the copolymerization of (1) and (2) and (b) heating themixture until an insoluble, in-

BIRGER W. NORDLANDER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,218,439 Rothrock Oct, 15, 19402,409,633 Kropa Oct. 22, 1946 2,433,616 Marple et al. Dec. 30, 1947

